fn main() { let t = { let mut line = String::new(); std::io::stdin().read_line(&mut line).unwrap(); line.trim().parse::<usize>().unwrap() }; for _ in 0..t { match solve() { Some(ans) => { print!("{}", ans[0]); for e in ans[1..].iter() { print!(" {}", e); } println!(); } None => println!("-1"), } } } fn solve() -> Option<Vec<usize>> { let (n, x) = { let mut line = String::new(); std::io::stdin().read_line(&mut line).unwrap(); let mut iter = line.split_whitespace(); ( iter.next().unwrap().parse::<usize>().unwrap(), iter.next().unwrap().parse::<usize>().unwrap(), ) }; if n * (n + 1) / 2 > x { return None; } let rem = x - n * (n + 1) / 2; let (q, r) = (rem / n, rem % n); let mut seq = (1..=n).rev().collect::<Vec<usize>>(); for i in 0..n { seq[i] += q + (i < r) as usize; } Some(seq) }